CologneBonn - Prague - Kiel meeting 2017 (CPK17):

The Footpoint

Relativistic disk and jet modelling of Sgr A* and M87

Scientific rationale

'The Footpoint' is located in the immediate vicinity of super massive black holes and characterized by the presence of an accretion disk as well as the footpoint of a relativistic jet. For a supermassive black hole at the lower end of the mass distribution the disk may be of a temporary nature and the jet may rather be a central wind. Alternatively this region is dominated by an advection dominated accretion flow in which neither disk nor jet are established. These interesting scenarii spawn a multitude of modeling efforts. The meeting touches on several of these efforts as well as on the radio to X-ray data that comprise the observational basis of the modeling and the investigation of physical properties.


Left panel Image Credit: Ralf Kaeler (KIPAC) and Jonathan McKinney (UMD)
Right panel A system showing two types of X-ray winds. Left: Pictorial representation of the energy released by the SMBH at the center of a galaxy (surrounded by an accretion disc), via collimated (in orange-red) and uncollimated (white) winds. Right: Simulations of Athena X-IFU spectra resulting from two types of so-called “ultra fast outflows” with higher velocity, higher ionization than those winds, seen only above 6 keV. (Credit: ESA/AOES Medialab/Figure and Caption adopted from 2017 Athena Calender).

The meeting builds on the tradition of previous Cologne-Prague-Kiel meetings: CPK13 , CPK15 , CPP15 , and CPK16 .


The meeting starts on May 8 (Monday) and ends on May 10, 2017 (Wednesday).

CPK17 Meeting Photos


Organizer: I.Physikalisches Institut, Universität zu Köln

Scientific participants:

Scientific and local organizing committee:

Andreas Eckart (chair of LOC) University of Cologne/MPIfR
Silke Britzen Max Planck Institute for Radioastronomy, Bonn
Wolfgang Duschl University of Kiel
Vladimír Karas Astronomical Institute of the Academy of Sciences, Prague/Charles University in Prague
Michal Zajaček (LOC, website) University of Cologne/MPIfR (former: Charles University in Prague)
Gerold Busch (LOC) University of Cologne


Castle Wahn , University of Cologne, Burgallee 2, 51127 Köln

Castle Wahn Tour (in German)

Scientific topics

Astronomy picture of the day
Astronomy Picture of the Day

Participants and Programme


Participant list

Confirmed participants

# Name Institute
1 Enmanuelle Mossoux Observatoire astronomique de Strasbourg/Groupe d’Astrophysique des Hautes Energies, Université de Liège
2 Vladimír Karas Astronomical Institute of the Czech Academy of Sciences
3 Lýdia Štofanová Charles University in Prague
4 Romana Mikušincová Charles University in Prague
5 Abhijeet Borkar Astronomical Institute of the Czech Academy of Sciences/Ph1 Uni Koeln
6 Wolfgang Duschl University of Kiel
7 Andreas Eckart University of Cologne/MPIfR
8 Michal Zajaček University of Cologne/MPIfR
9 Florian Peissker University of Cologne
10 Marzieh Parsa University of Cologne/MPIfR
11 Seyedeh Elaheh Hosseini University of Cologne/MPIfR
12 Madalina Badea University of Cologne
13 Matthias Subroweit University of Cologne
14 Gerold Busch University of Cologne
15 František Dinnbier University of Cologne
16 Jana Schneeloch University of Cologne
17 Silke Britzen MPIfR
18 Jae-Young Kim MPIfR
19 Rusen Lu MPIfR

Topic talks

Introductory presentation by Michal Zajaček and Silke Britzen: Download

Speaker Topic
Rusen Lu The event-horizon-scale structure of Sagittarius A* at a resolution of ~3 Schwarzschild radii
Enmanuelle Mossoux Sixteen years of X-ray monitoring of Sagittarius A*: Evidence for a decay of the faint flaring rate from 2013 August, 13 months before a rise in the bright flaring rate (Recent result: arXiv:1704.08102)
Enmanuelle Mossoux The X-ray shadow of the Circum-nuclear Disk
Jae-Young Kim Millimeter-VLBI observations of M87
Jae-Young Kim 3mm VLBI polarimetry of AGN sources
Matthias Subroweit Multi-waveband statistics of Sgr A*
Marzieh Parsa Galactic Center S stars
Vladimír Karas Black holes and magnetic fields
Abhijeet Borkar Radio/sub-mm observations of Sgr A*: Historical perspective
Andreas Eckart Galactic center: General
Andreas Eckart Galactic center: Physics
Michal Zajaček Neutron stars in the Nuclear Star Cluster
Michal Zajaček Nature of NIR-excess sources in the Galactic centre (Recent result: arXiv:1704.03699)
Silke Britzen Deep inside Galaxy M87: Turbulent loading leading to large-scale episodic wiggling (Recent result:press release)
Madalina Badea Models and Simulations of Galaxy M87
Romana Mikušincová Introduction to X-polarimetry: present status and future prospects
Seyedeh Elaheh Hosseini Detection of NIR-excess for stellar sources in the S-cluster
Florian Peissker Status of the DSO/G2 monitoring
Jana Schneeloch Galaxy evolution across optical diagnostic diagram

Social events


The maximum capacity is 30 participants, most of whom will be from Cologne, Bonn, Prague, and Kiel. In case you are interested in the meeting and would like to attend or give a talk, please register by sending an email to the the organizer Michal Zajaček (cc Andreas Eckart). Make sure the email contains the following information:

The Registration deadline is April 30, 2017.

The on-site registration of all participants is on Monday, May 8, from 9 am -10 am, or individually upon arrival, at Castle Wahn.

Background photo credit: NASA/ESA
Last change: 18/02/2017 by M. Zajaček (webmaster) .